hash.h

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/*
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Copyright (c) 2022, Stable Cloud Computing, Inc.
 
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modification, are permitted provided that the following conditions are met:
 
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   this software without specific prior written permission.
 
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*/
#ifndef _CRYPTO_HASH_H
#define _CRYPTO_HASH_H
 
#include <vector>
#include <string>
#include <memory>
#include <crypto/secvec.h>
#include <util/iobase.h>
 
// forward declarations
class HashBase;
class HmacBase;
 
namespace scc::crypto {
 
class Hash
{
public:
    enum Algorithm
    {
        md5_type        =1001,      // Note: the MD5 algorithm is not considered secure for cryptographic purposes, but has been included to support legacy services
        sha1_type       =1002,      // Note: SHA-1 is also considered insecure, SHA-2 (SHA-256) is suggested as an alternative.
        sha224_type     =1003,
        sha256_type     =1004,
        sha384_type     =1005,
        sha512_type     =1006,
        sha512_224_type =1007,      // 224 bit hash based on 512 bit blocks (performance better on 64 bit machines)
        sha512_256_type =1008,      // 256 bit hash based on 512 bit blocks (performance better on 64 bit machines)
        sm3_type        =1009,      // 256 bit hash based on 512 bit blocks (performance better on 64 bit machines)
    };
private:
    std::unique_ptr<HashBase> m_ptr;
    Algorithm m_alg;
public:
    static int alg_size(Algorithm alg)
    {
        switch (alg)
        {
            case md5_type:          return 16;
            case sha1_type:         return 20;
            case sha224_type:       return 28;
            case sha256_type:       return 32;
            case sha384_type:       return 48;
            case sha512_type:       return 64;
            case sha512_224_type:   return 28;
            case sha512_256_type:   return 32;
            case sm3_type:          return 32;
        };
        return 0;
    }
 
    Hash(Algorithm);
    virtual ~Hash();
    
    Hash(const Hash&) = delete;
    Hash& operator=(const Hash&) = delete;
 
    Hash(Hash&& other);
    Hash& operator=(Hash&& other);
 
    static bool supported(Algorithm);
 
    void reset();
 
    void update(const void*, int);
    void update(const std::vector<char>& v)
    {
        update(v.data(), v.size());
    }
    void update(const std::string v)
    {
        update(v.data(), v.size());
    }
 
    int get_tag(void*, int);
    int get_tag(std::vector<char>& v)
    {
        v.resize(size());
        return get_tag(v.data(), v.size());
    }
    int get_tag(std::vector<char>& v, int sz)
    {
        if (sz >= 0)    v.resize(sz);
        return get_tag(v.data(), v.size());
    }
 
    int final(void*, int);
    int final(std::vector<char>& v)
    {
        v.resize(size());
        return final(v.data(), v.size());
    }
 
    int alg() const { return m_alg; }
 
    int size() const { return alg_size(m_alg); }
};
 
class HashReader : public scc::util::Reader
{
    scc::util::Reader& m_rd;
    Hash& m_chk;
    SecVecChar m_buf;
public:
    HashReader(scc::util::Reader& rd, Hash& chk) : m_rd(rd), m_chk(chk) {}
    virtual ~HashReader() {}
    virtual size_t read(void* loc, size_t len)
    {
        m_buf.resize(len);
        int got = m_rd.read(m_buf.data(), len);
        if (got == 0)
        {
            return 0;
        }
        m_chk.update((char*)m_buf.data(), got);
        memcpy(loc, (char*)m_buf.data(), got);
        return got;
    }
};
 
class HashWriter : public scc::util::Writer
{
    scc::util::Writer& m_wr;
    Hash& m_chk;
public:
    HashWriter(scc::util::Writer& wr, Hash& chk) : m_wr(wr), m_chk(chk) {}
    virtual ~HashWriter() {}
    virtual size_t write(const void* loc, size_t len)
    {
        int put = m_wr.write(loc, len);
        if (put == 0)
        {
            return 0;
        }
        m_chk.update(loc, put);
        return put;
    }
    virtual void shutdown() {}
};
 
class Hmac
{
    std::unique_ptr<HmacBase> m_ptr;
    Hash::Algorithm m_alg;
public:
    Hmac(const void*, int, Hash::Algorithm);
    Hmac(const std::vector<char>& key, Hash::Algorithm alg) : Hmac(key.data(), key.size(), alg) {}
    Hmac(const std::string& key, Hash::Algorithm alg) : Hmac(key.data(), key.size(), alg) {}
    virtual ~Hmac();
    Hmac(const Hmac&) = delete;                 // no copy
    Hmac& operator=(const Hmac&) = delete;
    Hmac(Hmac&& other);
    Hmac& operator=(Hmac&& other);
 
    static bool supported(int);
 
    void init(const void*, int);
    void init(std::vector<char>& v)
    {
        init(v.data(), v.size());
    }
    void reset();
    void update(const void*, int);
    void update(const std::vector<char>& v)
    {
        update(v.data(), v.size());
    }
    void update(const std::string& v)
    {
        update(v.data(), v.size());
    }
    
    int final(void*, int);
    int final(std::vector<char>& v)
    {
        v.resize(size());
        return final(v.data(), v.size());
    }
 
    int alg() const { return m_alg; }
    
    int size() const { return Hash::alg_size(m_alg); }
};
 
}       // namespace
 
#endif